No 34 - 2010

Chlamydia 2009

According to the national laboratory notification system, there were 29,825 confirmed cases of chlamydia (oculogenital infection caused by Chlamydia trachomatis) in 2009. This corresponds to an annual incidence of 541 per 100,000 (532 per 100,000 in 2008). A total of 348,469 analyses were performed, and chlamydia was detected in 8.6% of those tested. The proportion of positives increased from 2002 to 2008, but no further increase was observed from 2008 to 2009, Table 1.

A total of 83% of males and 90% of females were aged 15-29 years, which is in line with observed in 2007 and 2008, Table 2.

For males, the highest incidence was seen among 20-year-olds, closely followed by 19-year-olds, Figure 1.

For females, the highest incidence was found among 19-20-year-olds in 2000-2006, among 18-year-olds in 2007, among 19-year-olds in 2008, and among 18-year-olds in 2009. Males constituted 38% of the cases.

This proportion increased steadily from 23% in 1994 to 37% in 2006-2008.

Geographical distribution

On the basis of the geographical location of the reporting departments, the male incidence in Copenhagen and Frederiksberg municipalities was 738 as opposed to 298-462 in the rest of the country. For females, the corresponding figures were 1,003 and 507-779, respectively. The M/F ratios of the incidences observed in Copenhagen and Frederiksberg municipalities (0.74), the previous Copenhagen (0.67) and Viborg (0.66) Counties were higher than the national average (0.62). In the remaining parts of Denmark, the M/F ratio of the incidences ranged from 0.53 to 0.62, and the highest incidence among males as well as females was seen in the North Denmark Region. This region also saw a considerable increase in gonorrhoea among young males and females in 2009.

Diagnostics

A total of 93% of the positive specimens were submitted by GPs, 6% by hospitals. All cases were detected by DNA amplification methods, except for nine cases detected by culture. Chlamydia was detected in urine samples in 9,958 cases, i.e. 33% of all cases (33% in 2008). Male samples constituted 89% of the positive urine samples (89% in 2008 and 91% in 2007). Urine was used as sample material in 78% of the male chlamydia cases (77% in 2008 and 70% in 2005). All laboratories reported positive findings in urine specimens. Rectal chlamydia was detected in 141 males (81 in 2008).

Chlamydia in children

Chlamydia was found in 299 children under 15 years of age (277 in 2008). Among these, 60 (20%) were under 1 year old, of whom 59 had a chlamydia eye infection and one had chlamydia of the respiratory tract. Among 20 children under 1 year with chlamydia eye infections, where age was stated in months, 12 were less than 1 month and six were 1 month old.

Urogenital chlamydia was detected in 217 girls, including one 12-year-old, 22 aged 13 years, and 194 aged 14 years.

Among boys, chlamydia was detected in one 13-year-old and 18 aged 14 years.

The incidence among 10-14-year-old girls was 127 per 100,000 (110 in 2008), while the corresponding figure for boys was 11 per 100,000 (nine in 2008).

Commentary

The number of analyses was 3% higher in 2008 than in 2009, and the number of cases diagnosed was 2% higher in 2008.

The incidence per 100,000 inhabitants was higher in 2009 than in 2008, and the trend towards spreading of the infection within younger age groups, regardless of sex, continued. This may indicate lack of use of condoms as chlamydia is a marker of unsafe sex.

The number of males with detected rectal chlamydia increased.

When rectal chlamydia is found in mails, they must also be tested for syphilis, HIV and lymphogranuloma venereum, EPI-NEWS 20/08 & 46/09.

(S. Hoffmann, Dept. of   Microbiological Surveillance and Research)

West Nile Fever in Greece

The Greek health authorities have reported 106 cases of West Nile Fever in the Macedonia Region of Northern Greece.  The majority of the patients had had meningitis and/or encephalitis and nine patients died, primarily persons with known risk factors. West Nile Fever virus has previously been detected in Southern Europe, and has also been found in mosquitoes in the Macedonia Region.

Heat and a high humidity may cause an increased occurrence of mosquitoes which transfer the West Nile virus.

No restrictions apply in connection with travels to the area of the outbreak, but travellers are recommended mosquito bite protection. For more information on West Nile Fever and its diagnosis, see EPI-NEWS 4/03.

Individually notifiable diseases and selected laboratory diagnosed infections  

(Department of Epidemiology)

25 August 2010